The summer I turned 10, we lived in a place which had a great outdoor swimming pool. Children under 10 were not allowed to visit this pool without an adult, and every day, I would beg my parents to take me swimming. At the end of the summer, the day I turned 10, I went along to the pool to take the swimming test which would allow me to visit the pool unaccompanied.
The test involved jumping in at the deep end and then swimming eight lengths of the pool. I was a slow swimmer, but could plod along for hours if I chose to - and that day, I did choose to. Having done my eight lengths, I kept going, and didn't get out until I'd swum 100 lengths.
On hearing about my 100 lengths, my second brother had to go down to the pool and beat my record. He has always been very sporty and competitive and was a strong swimmer. He set off like a bat out of Hell, and after about 60 lengths he was flagging. Fortunately for him, at that point everyone was required to get out of the pool for some sort of routine maintenance, and having caught his breath, he got back in and did another 60. That 120 lengths tested him to his absolute limit.
The next day, I went down to the pool again. In my slow, plodding way - a girlie breaststroke in which I failed ever to put my face in the water - I knocked off 123 lengths. When I got out of the pool, my lips were blue, but I was deeply satisfied with my achievement.
My mother wouldn't let my brother try again - she knew how competitive we both were, and how unwilling to admit defeat, and my brother had really struggled to complete his 120 lengths. She put an end to the competition before one of us drowned rather than give in to the other.
The memory of this long, pointless swim has stood me in good stead many times in life. I know I'll never be the fastest or the best at anything I try. But I also know that, like the tortoise in Aesop's fable, I'll plod along until I complete whatever I've started.
This time last year, I was training for a marathon. I was overweight and unfit, and when I started training, I had never run more than half a mile in my life.
I completed the marathon in a little over six and a half hours. I walked most of the last six miles, and even when I was running, I was so slow that I was being overtaken by walkers. But I completed the 26.2 mile course within the time allotted (the course closed after eight hours), and I got exactly the same finisher's medal and t-shirt as the super-sporty people who finished in half the time.
My mother always tried to teach us that talent and knowledge alone are not enough to make a person successful, and that what you really need in life is application.
As a teacher, I've absorbed that lesson. I'll give hours of my time to a student who is prepared to follow advice and put in the effort needed to pass their exams, and I'll do everything in my power to try to help them to succeed.
But at the moment I'm frustrated. I have one student who is failing. My colleagues and I have given this person endless amounts of time, energy, concern and sympathy. In return, we get lies, excuses and missed deadlines.
Maybe it's time to chuck her in the pool and tell her to start swimming.